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NA 3.1L=>head & camshaft questions. No shortcuts, max


zredbaron

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Man, I feel bad for you Mark. Every dyno session, with the latest iteration of the motor anyway, has been a clusterfuck. I hope you get it sorted.

I am pretty sure you're running the Porsche style CVs. I've heard of the bolts coming loose on quite a few different Datsuns. Might be a good idea to safety wire them. Could do the same with the driveshaft bolts too if you want.

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@zredbaron

 

Love the information and feedback you are providing! Keep it up by all means! 

If you could answer a few quick questions in regards to some other details of your equipment I would really appreciate it. What diameter runners or brand of headers are you running and I know you mentioned you were running 65F8 idle jets, are you still running those when you were testing out the 38mm venturis? 

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Thanks Jon. I was pretty much in shock all day on Friday. I couldn't believe what was happening as it unfolded. Unreal. I agree, I'd be a lot more comfortable if the inner bolts were also safety wired.

 

rustler753, I'm running Stahl headers with 1 5/8" primaries, and 2.5" secondary collectors. The two 2.5" pipes are passed through a 20 degree merge collector, then expanded from 2.5" to 3" with 3" mandrel exhaust all the way back. Two straight through Magnaflow mufflers in series. I've been running 75F8 idle jets for the most part, with 70F8 and 80F8 also being used depending on the day and carb setup (venturis, horns, etc).

 

Edited by zredbaron
added jets info
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1946301743_KSDynoTightGraph5_18_2018.thumb.JPG.efd7fd75f97d776c2dec98cd26a70f8e.JPG05.18.2018 Dyno Day Report

 

  1. 630am - 815am
    • I arrive at my road testing location, and continue to prep for my dyno appt at 9am
    • I continue to refine the performance of the short stack webers
    • I achieve a near-constant 13.0 AFR from ~4000-7000 RPM
    • Car is smooth as silk at the top of 4th gear, 120ish?
    • I have known good jet settings for 38mm venturis with long stacks, and 40mm venturis with short and long stacks, and have swapped back to known good settings several time this week. Repeatable.
  2. 845am
    • Unload car at dyno shop
    • Car fires right up, I turn it off after driving it off trailer.
    • Tech wants to get in the car and put it on the dyno.
    • Against my better judgment, I allow a young tech to attempt to start my triple carbs (neither warm nor cold motor)
  3. 915am
    • At this point I kicked the tech out of the car and I'm trying to start it.
    • Flooded? Fouled plugs?
    • I decide to refuel, allowing time for the flooded carbs to clear.
    • Won't start
  4. 10am
    • New NGK plugs installed
    • Fires right up, I drive it onto dyno
    • Tech has me accelerate slightly to set the wheels.
    • I am already alarmed by dyno noises and vibrations, I am assured this is normal
    • It's not like I've never dynoed before
  5. 1030am
    • Car is NOT the same car that I've been tuning all week!
    • Making jet changes are having OPPOSITE effects then what happens roadside!
      • Example:  changing main jets 10 up or down DOES NOTHING!?
      • Example: changing air corrector jets now behave as if the main jet is being changed?
    • Additionally and separately, my ignition is being screwy
      • A few times, the rev limiter did not kick in AT ALL
      • Several times, the car wouldn't accelerate on the dyno, but would simply hesitate and chill out and get groceries
      • Several times, while getting groceries on the dyno, VTEC or something kicked in because the acceleration would suddently PULL VERY HARD.
    • Pulls back to back did NOT have the same performance.
      • We started to not trust the data, sometimes doing 3 pulls for every adjustment.
    • WTF is going on?
  6. 1130am
    • Despite that the rules of tuning are now unpredictable, despite that my known settings are now shit...
    • I finally find a good AFR again, very near my 13.0 AFR that was attained roadside that morning
    • Time to move to timing
      • Dyno is scheduled for another customer at 2pm!
      • At this point all I want is to capture data for the Weber short and long stacks
  7. 12pm
    • I start messing with 1000RPM timing
    • I get my triples idling very nicely with a screwdriver
    • I start messing with 3000RPM timing
    • Engine is hot, needs to cool
  8. 1230pm
    • Tech announces he is going to lunch
    • No other techs around
  9. 1pm
    • Pulls resume
    • I am less desensitized to the vibrations
    • I continue to express concerns and I am told all is normal
  10. 115pm
    • Eff this, I'm getting my car outta here
    • I drive off the dyno and onto the street, vibes are insane, loud at 35mph
    • Day is done
  11. 215pm
    • Drop my car off at a general auto place to investigate on a lift
    • They tighten the driveshaft and right CV axle (inner bolts)
  12. Evening
    • I pushed myself so hard this week that I start shaking and aching and getting sick
    • Straight to bed around 7pm
  13. Weekend
    • Saturday - rest. I skip the first race the car can actually enter... because the driver can't go physically.
    • Sunday - autocross. Car kicked my ass, in a good way. Couldn't get the rear to settle down, which was delightful.
    • Not sure if I had "fun." Big losses this week. That's sad.
  14. Ignition
    • My ignition was crippled by something that day.
    • The hall effect sensor is supposed to negate interference?
    • Haven't called Electromotive yet. Depressing. I will.
    • My theory: the dyno's ignition inductance pickup was near my hall effect sensor's harness, where the sensor wire is less shielded for a few inches to allow the sensor and XDI harness to clip together.
    • I suspect if this had been relocated, the issue would have cleared. (Some positions definitely made it worse!)
  15. Dyno Graphs
    • The way the dyno loaded up (very delayed)... it was very hard to scientifically produce consistent dyno runs.
    • You can see some really screwy dyno plots. The ignition pickup had a really hard time, clearly.
    • I attempted to attain WOT by 3500 and 4000 RPM as the engine tune allowed.
    • In most cases, if I rolled into WOT slowly, it worked out. If I rolled quickly, it would be a wasted dyno pull (delayed dyno loading).
    • A few times I forgot I was supposed to achieve WOT (for consistent analysis of what the change did) and throttled the carbs through the reverb RPM range.
    • Very interesting to look at the torque plots of the throttled runs! WOW! (Enter driver as a patch! Haha.)
  16. Summary
    • Phudge. What the crap, even?
    • I'm still going to mess with a few of the air horns for awhile.
    • I'll still come back... not at this dyno.
    • The staff, to me, was more interested in getting through their day than helping their customer accomplish anything.
    • They dismissed my concerns about ignition and vibrations. Not helpful.
    • Sigh...

 

A not-quite what we want to hear video:

https://www.youtube.com/watch?v=vk_MpV3F9Ys

 

 

 

20180518_094748.jpg

20180518_094712.jpg

 

IMG_5168.thumb.JPG.b1d685dcb444f051d5e329da86c91246.JPG

IMG_5117.JPG

 

KS Dyno Throttling Graph 5.18.2018.JPG

KS Dyno HP-TQ Graph 5.18.2018.jpg

KS Dyno AFR-TQ Graph 5.18.2018.jpg

Edited by zredbaron
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Sad to read this. I know stuff happens, but the shop should have reacted. If there was any doubt the RPM pickup might be causing an issue, then DUMP it! You don't need it anyways. I'm sure Dyno Dynamics have a sync tool for roller speed to engine RPM. Set it and forget it.

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  • 1 month later...

I'm still here and making significant progress with my intake tuning.

 

At present, I can report that all aftermarket horns have outperformed the Weber straight horns, both short and tall. I have further invested in some custom machining solutions, one of which has really paid off (holy crap, I thought the car was singing before!) and is now very happy to quickly change engine speeds up and down with less resonance and gargling, even under 4k. I have another custom machining solution in the works, because well, my last three gut-instincts have been in the right direction and I'm still gaining lots of smoothly-delivered torque under the curve. And I still think I can have my peak power, too. No way I'm quitting while I'm ahead.

 

Why am I not sharing the actual details? Because I have another dyno date set and I'm tired of saying I'm going to deliver data. This might be my last foreseeable dyno visit. "Maybe I'll have data, maybe I won't." At a minimum I will share my qualitative comparisons as well as my jetting combinations (because the changes in jets reveal how the swapped intake part affected the AFR plot). Ideally this information will be accompanied by dyno plots, but I have abandoned my mission to have an R&D experience.

 

If I'm not already having an R&D experience then I should just give up my keys now. It's way past time to officially tune the engine timing and get an official, satisfactory baseline.

 

As always, I'll still share everything I have learned and I will post pictures of my custom machining solutions, whether they work or not.

 

EDIT - photos added showing some of the different air horns, mounted. (no I didn't ever fire it up this way)

IMG_5199.JPG

IMG_5192.JPG

Edited by zredbaron
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  • 3 weeks later...

Really looking forward to the data you are willing to share. I am heading towards a new setup with 38mm or 40mm chokes on my weber 45s so I am very curious about all your jet settings. I asked early about a few things like your idle jets but I'd love a bigger picture to see the direction you went with each jetting option we have available. 

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On ‎7‎/‎14‎/‎2018 at 10:04 AM, munters said:

A question where did you find the throttle lever with a hole (screw through) and idle adjustement for the left carb side?

Thanks Marcel

 

Hi Marcel. I'm not sure I'm following you. 

 

I do have custom throttle levers with a set screw. The purpose is to hold position throttle arm angle on the round throttle bar, and not slip. Metal tabs were welded and tapped, and then the arms were custom coated to match OEM Weber.

 

They do not have adjustments for idle. Idle speed is controlled by the carburetor idle speed screws (1 per carb) and the adjusting the lengths of the connecting links between the custom throttle levers and the carburetor throttle.

 

It isn't the best design / best welds. I broke one of the welds too easily. Very disappointing after all that effort. Now it all has to come off and be resynched...IMG_4268.thumb.JPG.17998ef56dc3bf859b8d1148433071ba.JPGIMG_4372.thumb.JPG.63860832c9e277a991c44a28c9d43f36.JPGIMG_4985.thumb.JPG.f201b1347e6571c902ba9c0961c468b5.JPG

 

 

Edited by zredbaron
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1 hour ago, rustler753 said:

Really looking forward to the data you are willing to share. I am heading towards a new setup with 38mm or 40mm chokes on my weber 45s so I am very curious about all your jet settings. I asked early about a few things like your idle jets but I'd love a bigger picture to see the direction you went with each jetting option we have available. 

 

Prior to my velocity stack hacks, I would have advised the 40mm venturis exclusively for drag/road racing (38mm for all else).

 

If you are ok with the coin required to upgrade and possibly partially/fully mod your intake parts (three options), you will not be disappointed by 40mm venturis fitted with 47-49mm ID stacks.

 

I apologize for being vague. (I want to make sure I have my notes in front of me.)

 

My dyno date was rescheduled, not due to my schedule. So it goes. I'm not sure when the reattempt will be. I'm racing almost every weekend until October, so it might have to wait until fall. I don't remotely lack for torque or power, so it won't impact my racing as much as a throttle cable upgrade might.  :2thumbs:

 

I've been carrying around a folder with pages of my jet settings. I need to organize it and figure out how to best present the highlighted data.

 

I'll deliver.

Edited by zredbaron
Parenthetical Details
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21 hours ago, zredbaron said:

 

Prior to my velocity stack hacks, I would have advised the 40mm venturis exclusively for drag/road racing (38mm for all else).

 

If you are ok with the coin required to upgrade and possibly partially/fully mod your intake parts (three options), you will not be disappointed by 40mm venturis fitted with 47-49mm ID stacks.

 

I apologize for being vague. (I want to make sure I have my notes in front of me.)

 

My dyno date was rescheduled, not due to my schedule. So it goes. I'm not sure when the reattempt will be. I'm racing almost every weekend until October, so it might have to wait until fall. I don't remotely lack for torque or power, so it won't impact my racing as much as a throttle cable upgrade might.  :2thumbs:

 

I've been carrying around a folder with pages of my jet settings. I need to organize it and figure out how to best present the highlighted data.

  

I'll deliver.

 

Absolutely no worries, I am a patient man.

 

Our motor setups are similar, but I have been finding upper end power a little lacking with my 36mm venturis so its exciting for me to do a comparison between the two. I have been planning for some time for an exhaust/intake update so the more data I have the better. You put it well; there is certainly a lot of coin involved if you are going through all the jet settings so I want to try to get it right. Only major glaring difference I see between your testing environment and mine is elevation as I am at 5,000 ft up so I will definitely keep that in mind when you present your data. 

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  • 3 months later...

@zredbaron

 

Sorry to be a bother, but I have been messing with tuning my Z recently and was hoping I could reference some data you have gathered. It's been a few months since I asked so I figured I would check back in and see if you would be willing to divulge what you have learned and data you gathered during your trials with chokes, jetting settings and velocity stack tryouts. 

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Bah! My apologies good sir. I burnt myself out trying to keep the car in working order and finishing the racing season.

 

Tell you what... PM me and we can coordinate offline / phone call that way you aren't waiting for my presentation! No one wants that. 

 

I haven't forgotten and still plan on at least one dyno session this year with some of the data that I didn't collect last time. Evidently L6 intake data remains high on my list to contribute to the S30 community!

 

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  • 8 months later...

For those that aren't big on reading, I'll put this first! I'm not big on social media, so the following invite to this YouTube premiere has not been advertised anywhere online. This thread is the first online announcement.

 

I invite you all to join me in watching my racing film (2017 memoir) this Saturday, July 13, 2019 @ 0930am PST (GST -8) on YouTube.      

  • 125++ hours editing (24 minute film).
  • 19+ years of dedication (21 years now in 2019)
  • 3"+ of receipts
  • Seriously-satisfying images and sounds
  • I don't care much if the video goes viral, but I would enjoy watching it live with those who are available.
  • It's a major life event for me.... Cheers! I hope you can make it, and if not, I know you will enjoy it whenever you have the time.  :2thumbs:

 

Ok. For those who like updates.... sorry it's been so long! I have delayed mostly because I'm a perfectionist and lately that results in inaction more often than activity. So it goes.

 

I ordinarily would post pictures but I'm just not organized enough right now. Better to at least check in...

 

  • Ok, so... belated update... but 2018 was a dope ass racing season!
    • (I didn't share. I don't really do social media much. I'm starting to crawl out of my turtle shell again. Thanks for the canvas to express.)
    • It was a wild success, even though I didn't really experience it as pleasant at the time. (Depression? Blood, sweat and tears? Same same?)
    • I didn't win anything other than a couple man-fridge magnets in classes too small... attendance prizes in truth.
    • I beat only one of my targeted peer benchmarks (a B Prepared 80s Corvette), but I felt like I had a few wins on several other non-timed categories. LOL
      • Most eye appeal (usually tech inspectors missed things because of shiny vintage)
      • Best sound (too loud for many but still top notes to a surprising high % of people that just had to say so)
        • (credit to the legendary L6, John Coffey's R&D, and of course Joe Harlan the builder!)
      • Most fun ("crisp horsepower," "smooth skating" (end of season),  "what just happened," "now my adrenaline is up (faster driver+car)"
      • Purist / vintage award
  • Racecar upgrades included (photos one day when I organize offline stuff from last year):
    • Welded frame rails
    • Custom front frame swaybar mounting [system?]
      • Photos one day when I organize my offline photos
      • 2 Plates welded to both top and bottom of frame rails
      • 2 additional plates for clamping:
        • One plate had a long hollow finger that passes through the frame rail
        • and conically fits into other side
      • Long stud through all of it and holding pillow blocks at the bottom
    • Front Brake rotors
    • Custom aluminum driveshaft (third party vendor via MSA... anyone know? nice product.)
    • 350/300# springs and later 400/350# springs (and a lot of rear rebound adjustments!)
  • Racecar problems included
    • Drivetrain ripped apart
      • Wolf Creek CV kit:
        • Excessive play
        • Adapter plate loose.
      • Retightened.
        • Happened again.
        • Found walleyed adapter.
      • rebored
        • Larger bolt, higher torque
        • safety wire interior adapter (yes! impossible labor)
        • safety wire exterior adapter (again, new custom bolts)
        • safety wire driveshaft
        • safety wire inboard adapter (diff side, still)
      • Halfshalfts restored, CV axles are trash
        • Axles literally developed play between the shaft and the splines (not a solid piece!?) - unacceptable!
        • 300bhp through a 4.37 Quaiffe on 245mm Hoosiers
        • U-joints  Survived even with ATB (!)
      • R180 rebuild #1
        • Play can be felt between OEM stub axle splines and Quaiffe
        • After the rebuild, it behaved like a welded diff - spinouts caught me off guard but powersliding was way easier - I'm used to ATB!
      • Moustache bar snapped
        • Straight up sheared in half (!)
        • got torque?
        • stock halfshafts with spicer u-joints still intact (NOTE FOR BUDGET RACERS!!!)
        • Holy R180, batman!
      • R180 rebuild #2
        • New donor ring and pinion (4.37, 1982 Datsun 720 King Cab 4x4)
        • There's a reason the Quaife is warrantied for lifetime under racing conditions!
        • Evidently too much Loctite was the cause of the ATB behaving like a welded diff
        • Blew my mind, and that of the AAMCO staff
        •  
      • Quaife wins this round!
    • Slicks died - twice
      • Brake bias a major issue
      • Aggressive driver a more major issue
      • 2 bias proportioning valves installed (1 removed)
    • Tachometer died
      • Can only blame my younger, amateur self since I was the one whoinstalled it
    • Season end
      • I miss a "very high speed" autocross event in Montana (Top Gun) 
      • I literally hauled 10 hours and fly my father from out of state to attend
      • I miss a "high speed" autocross event in Spokane, WA (Octocross)
  • What's Next?
    • I haven't driven my car in 2019 yet
      • Will focus on seat time for remainder of summer
      • Intake R&D (air horns, venturis, etc.) is still pending -- for this upcoming winter (no foreseeable overhauls for once)
    • Fabrication nearly complete:
      • Ermish Racing CV axle conversion (chromoly stubs and outers, no adapter plates anymore)
      • Custom Woodward steering column upgrade
      • Throttle cable upgrade, including a fine-idle speed adjustment cable implemented via OEM interior choke handle
      • Rear brake line and e-brake cable repairs
      • Rear sway bar installed for first time since 2009
    • Will perform hot leakdown test to confirm engine health
    • First ever time-trial / HPDE for the car (and driver) on 8/3/19 (engine builder Joe Harlan will be an instructor on his home course, Portland Int. Raceway)

 

 

Edited by zredbaron
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